Air quality in Karatsu, Japan today

Mr. Duck’s Air Quality Score

Good air today for Karatsu, Japan

⚠️ This website is currently under active development. Some data may be incomplete or temporarily inaccurate. For health-critical decisions, please verify information through official government or environmental sources.

Categories follow US EPA AQI breakpoints for PM (estimate from latest valid measurements; this project does not compute EPA NowCast/24-hour AQI yet).

This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.

Air quality today

The air quality in Karatsu is classified as Good today. The primary pollutant identified is PM2.5, with a reference concentration of 3.0 µg/m³ based on six valid measurements reported through OpenAQ.

These values reflect the current monitoring snapshot for the city. This page is informational; for health guidance, use official sources such as EPA AirNow or WHO.

Latest sensor values

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

What the data includes

The data set for Karatsu includes five measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO₂), total nitrogen oxides (NOX), fine particulate matter (PM2.5) and sulfur dioxide (SO₂). These values come from six individual rows of observations that are grouped into two monitoring stations, all located at the same address in 唐津市二夕子 1‑7‑83. The most recent timestamp for every pollutant is 2026-02-10 22:00 UTC, which falls within the “updated within three days” freshness window, so the information reflects very current conditions.

PM2.5 values range from a minimum of 1.0 µg/m³ to a maximum of 3.0 µg/m³, with a median of 2.0 µg/m³ and the 10th‑percentile at 1.2 µg/m³ while the 90th‑percentile sits at 2.8 µg/m³. In contrast, NO, SO₂ and their related compounds are consistently recorded as zero across all rows, showing no detectable concentration at the time of measurement. Both NO₂ and NOX appear at a uniform level of 0.002 ppm in every record, giving them identical minima, maxima, medians and percentile values.

Because the dataset is limited to two stations at a single site, spatial coverage within Karatsu is narrow; conditions elsewhere in the city may differ from those captured here. Nonetheless, the data are fresh, with all pollutants reported on the same recent date, and they provide a clear snapshot of current ambient levels for the listed contaminants.

Learn more about sources and filtering: About the data.

Trusted references: WHO (Air pollution) · US EPA AirNow · European Environment Agency (Air)

Latest sensor values (bars)

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

Data notes

The data shown for Karatsu reflects six valid measurements and is updated within 3 days, with the most recent reading recorded on 2026‑02‑10 at 22:00 UTC. While this snapshot provides a current overview of air quality across the city, conditions can differ by neighborhood and change throughout the day, so local variations may exist beyond what is displayed here.

OpenAQ station rows